feat(threedigit): same as twodigit but show 3 digit if sum > 99

README.md

@@ -8,6 +8,7 @@ Compilation of my DOS x86 Assembly programs
 ## Programs
 
 - [TWODIGIT](TWODIGIT.ASM) - Add 2 numbers, show 2 digits if sum > 9.
+- [THREEDIGIT](THREEDIGIT.ASM) - Same as `TWODIGIT`, but show 3 digits if sum > 99.
 - [DIVISION](DIVISION.ASM) - Divide 2 numbers, show quotient with 5-digit precision.
 
 ## License

THREEDIGIT.ASM

@@ -0,0 +1,246 @@
+jmp start
+
+    nm1     db    3, 4 dup(0)
+    nm2     db    3, 4 dup(0)
+    quo     db    0
+    rmd     db    0
+    rs1     db    0
+    rs2     db    0
+    rsf     db    0
+    fnm     db    0
+    snm     db    0
+
+    ms1     db    'Enter 1st number: $'
+    ms2     db    'Enter 2nd number: $'
+    ms3     db    'Sum: $'
+    clf     db    13,10,'$'
+
+start:
+
+    ; clear registers
+    call clear_r
+    call clear_v
+    
+    ; display message
+    lea dx,ms1
+    mov ah,9
+    int 21h
+    
+    ; get input
+    lea dx,nm1
+    mov ah,0ah
+    int 21h
+    
+    ; print line
+    call n_line
+    
+    ; display message
+    lea dx,ms2
+    mov ah,9
+    int 21h
+    
+    ; get input
+    lea dx,nm2
+    mov ah,0ah
+    int 21h
+
+    ; print line
+    call n_line
+    
+    ; convert inputs to number
+    call cnv_nm1
+    call cnv_nm2
+    
+    ; clear registers
+    call clear_r
+    
+    ; add converted input 
+    mov al,rs1
+    add al,rs2
+
+    mov rsf,al ; store result int result final
+    
+    ; print sum message
+    lea dx,ms3
+    mov ah,9
+    int 21h
+    
+    ; clear registers
+    call clear_r
+
+    ; if result is greater than 100
+    cmp rsf,100
+    jae call_d3
+
+    ; if result is greater than 10
+    cmp rsf,10
+    jae d2
+    
+    ; if result is less than 10
+    jmp d1
+    
+    ; stop program
+    int 20h
+
+cnv_nm1:
+    mov al, [nm1+2] ; get the first digit
+    sub al, '0'     ; convert to a number
+    mov fnm, al     ; store the first digit
+    
+    ; set result
+    mov rs1, al
+    call clear_r
+
+    ; check if there is a second digit
+    mov al, [nm1+3]
+    CMP al, 13
+    je fun_ret
+    
+    ; if there's a second digit
+    mov al, [nm1+3] ; get the second digit
+    sub al, '0'     ; convert to a number
+    mov snm, al     ; store the second digit
+    
+    ; multiply first digit by 10
+    mov al, fnm
+    mov bl, 10
+    mul bl
+    
+    ; add second digit to result
+    add al, snm
+    mov rs1, al
+
+    ret
+
+cnv_nm2:
+    mov al, [nm2+2] ; get the first digit
+    sub al, '0'     ; convert to a number
+    mov fnm, al     ; store the first digit
+    
+    ; set result
+    mov rs2, al
+    call clear_r
+
+    ; check if there is a second digit
+    mov al, [nm2+3]
+    CMP al, 13
+    je fun_ret
+    
+    ; if there's a second digit
+    mov al, [nm2+3] ; get the second digit
+    sub al, '0'     ; convert to a number
+    mov snm, al     ; store the second digit
+    
+    ; multiply first digit by 10
+    mov al, fnm
+    mov bl, 10
+    mul bl
+    
+    ; add second digit to result
+    add al, snm
+    mov rs2, al
+
+    ret
+
+call_d3:
+    call d3
+    jmp end
+
+fun_ret:
+    ret
+
+d1:
+    mov dl,rsf
+    or dl,30h
+    mov ah,2
+    int 21h
+
+    int 20h
+
+d2:
+    ; divide result by 10
+    mov al,rsf
+    mov bl,10
+    div bl
+    
+    ; store results
+    mov quo,al
+    mov rmd,ah
+    
+    ; print quotient
+    mov dl,quo
+    or dl,30h
+    mov ah,2
+    int 21h
+    
+    ; print remainder
+    mov dl,rmd
+    or dl,30h
+    mov ah,2
+    int 21h
+
+    int 20h
+    
+d3:
+    ; divide result by 100
+    mov al,rsf
+    mov bl,100
+    div bl
+    
+    ; store results
+    mov quo,al
+    mov rmd,ah
+
+    ; print quotient
+    mov dl,quo
+    or dl,30h
+    mov ah,2
+    int 21h
+    
+    ; divide remainder by 10
+    mov al,rmd
+    mov bl,10
+    div bl
+
+    ; store results
+    mov quo,al
+    mov rmd,ah
+
+    ; clear registers
+    call clear_r
+
+    ; print quotient
+    mov dl,quo
+    or dl,30h
+    mov ah,2
+    int 21h
+
+    ; print remainder
+    mov dl,rmd
+    or dl,30h
+    mov ah,2
+    int 21h
+
+    int 20h
+
+end:
+    int 20h
+    ret
+
+n_line:
+    lea dx,clf
+    mov ah,9
+    int 21h
+    ret
+
+clear_r:
+    xor ax,ax
+    xor bx,bx
+    xor cx,cx
+    xor cx,dx
+    ret
+
+clear_v:
+    mov ax,3
+    int 10h
+    ret